immel



Feb. 14, 1956 R. B. IMMEL SNAP-ACTION SWITCH 3 Sheets-Sheet 1 Filed Nov.28, 1951 INVENTOR Rcllph B. Immel. W

wafizam.

ATTORNEY Feb. 14, 1956 R. B. IMMEL 2,734,959

SNAP-ACTION SWITCH Filed Ncv. 28, 1951 3Sheets-Sheet 3 ff F' .II. Fig.7.0

WITNESSES:

INVENTOR W Ralph B. Ir n mel. 2 m, MM

ATTORNEY United States Patent SN AP-ACTION SWITCH Ralph B. Immel,Williamsville, N. Y., assignor to Westinghouse Electric Corporation,East Pittsburgh, Pa., a corporation of Pennsylvania Application November28, 1951, Serial No. 258,656 25 Claims. (Cl. Zea-s7 My inventionrelates, generally, to electric switches and, more particularly, toswitches which operate with a snap action.

An object of my invention is to provide a switch having a precise andpositive action.

Another object of my invention is to provide a multiposition snap-actionswitch.

A further object of my invention is to provide a snapacting switch ofthe tubular type having a pivotally mounted operating handle.

Still another object of my invention is to reduce friction between themembers of a switch of the snap-acting type.

A still further object of my invention is to provide a switch having abridging contact member which is spring supported within the switch.

A more general object of my invention is to provide a snap-acting switchwhich is simple and reliable in operation and which may be economicallymanufactured.

Other objects of my invention will be explained fully hereinafter orwill be apparent to those skilled in the art.

In accordance with my invention, the bridging contact member of asnap-action switch is connected through a lost-motion means to anoperating handle by toggle springs which cooperate with a spring arm orarms formed integrally with the bridging member to maintain contactpressure and to actuate the bridging member from one position to anotherwith a snap-action when the handle is operated.

For a better understanding of the nature and objects of the invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawings in which:

Figure 1 is a view, in side elevation, of a switch embodying theprincipal features of the invention, the cover being removed;

Fig. 2 is an enlarged and exploded view of certain parts of the switch,the parts being shown in perspective;

Fig. 3 is a view, in section, of a modified switch;

Fig. 4 is a view, similar to Fig. 2, of parts of the switch shown inFig. 3;

Fig. 5 is a view, partly in side elevation and partly in section, ofanother modified form of switch;

Fig. 6 is a view, similar to Fig. 2, of parts of the switch shown inFig. 5;

Fig. 7 is a view, partly in side elevation and partly in section, ofstill another modified form of switch;

Figs. 8 and 9 are views, in side elevation, of the switch shown in Fig.7, the operating handle and the contact members being in difierentpositions;

Fig. 10 is a bottom plan view of the switch shown in Fig. 7 with thecover in place, and

Fig. 11 is a view, similar to Fig. 2, of parts of the switch shown inFig. 7.

Referring to the drawings, and particularly to Figs. 1 and 2, the switchshown therein comprises a base 10 having holes 11 therein for attachinga cover (not shown) to the base 10 by means of rivets or bolts. The base10 and the cover are preferably molded from a suitable insulatingmaterial. An opening 12 is provided in the base 10 for an operatinghandle 13 which is utilized to actuate the switch mechanism in a mannerwhich will be more fully described hereinafter.

Upper stationary contacts 14 and lower stationary contacts 15 aremounted on the base 10. Each upper contact 14 is supported by agenerally U-shaped bracket 16 which is attached to a terminal 17, whichmay be molded into the base 10. Each lower contact 15 is supported by agenerally Z-shaped bracket 18 which is attached to a terminal 17.Terminal screws 19 are provided for making electrical connections to theterminal members.

A generally rectangular bridging contact member 21 is movably disposedbetween the upper contacts 14 and the lower contacts 15. The member 21carries upper contacts 22 and lower contacts 23, which are disposed toengage the upper contacts 14 and the lower contacts 15, respectively,under predetermined conditions. The bridging contact member 21 may bestamped from a relatively thin sheet of a resilient good electricalconducting material, such as Phosphor bronze or beryllium copper. Thecontacts 14, 15, 22 and 23 are composed of a good electrical conductingmaterial, such as silver or a silver alloy.

As shown most clearly in Fig. 2, the bridging contact member 21 has twopairs of integrally formed spring arms 24. The arms 24 are arranged inoppositely disposed pairs with the ends of each pair spaced apredetermined distance apart. The end of each arm 24 has a projection 25extending therefrom. A semi-cylindrical portion 26 is formed in thecenter leg of the member 21. A similarly formed strap 27, which may beattached to the member 21 by rivets 28, clamps a bearing bushing 29 tothe member 21. A bearing pin or shaft 31 is mounted in the bearingbushing 29. The ends of the shaft 31 are disposed in openings providedin the base 10 and the cover for the switch, thereby supporting thebridging contact member 21.

The actuating mechanism for the switch comprises the handle 13, anoperating lever 32 and a pair of generally U-shaped toggle springs 33which are joined together by an integrally formed bar 34. The handle 13may he threaded into an opening 35 in the operating lever 32. The lever32 has spaced integrally formed legs 36 having openings 37 thereinthrough which the ends of the shaft 31 are inserted. The lever 32 alsohas downwardly extending projections 38 which straddle the tie bar 34for the toggle springs 33. The distance between the projections 38 isconsiderably greater than the width of the tie bar 34, thereby providinga lost-motion connection be tween the operating lever 32 and the togglesprings 33. The toggle springs 33 have integrally formed spaced legs 39with openings 41 therein through which the ends of the shaft 31 are alsoinserted. Thus, the bridging contact member 21, toggle springs 33 andthe operating lever 32 are movable about the same axis 31 when theswitch is assembled.

As shown in Fig. 2, the ends of the arms of the U- sh'aped togglesprings 33 are generally V-shaped with an opening 42 in each arm. Theparts of the switch may be assembled by inserting the projections 25 onthe spring arms 24 into the openings 42 in the toggle springs 33 andinserting the ends of the shaft 31 into the openings 41 in the legs 39of the toggle springs. The operating lever 32 may then be placed inposition over the toggle springs 33 and the ends of the shaft 31inserted into the openings 37 in the legs 36 of the operating lever 32.The entire movable assembly may then be placed in the casing with thehandle 13 extending through the opening 12. The cover may then beattached to the casing.

In order to obtain the desired snap action of the switch, the distancebetween the V-shaped ends of the toggle jections 25 011 the spring arms24' into the openings 42 in the spring toggle 61. The bearing pin 64 maythen be inserted through the openings 63 in the legs 62 of the springtoggle and through an opening 72 in the bearing block 65, therebysupporting the spring toggle 61 and the bridging contact member 21. Theoperating lever 68 may then be placed in position with the handle 13extending through the opening 12 in the base, after which the cover forthe casing may be attached.

When the switch is assembled, the spring toggle 61 and the operatinglever 68 are movable about the same axis since the pins 71, whichsupport the operating lever 68, are in alignment with the bearing pin 64for the spring toggle 61. The switch is operated in the same manner asthe ones shown in Figs. 1 and 3 by actuating the operating handle 13'.However, in the present structure the bridging contact member 21 isself-aligning, since it is supported by the toggle spring 61 and not ona fixed axis, as in the structure shown in Figs. 1. and 2. Accordingly,quick movement of the bridging contact member is assured when the togglespring passes overcenter as the handle is actuated. Slow action, causedby misalignment of the parts of the switch, is eliminated.

The switch shown in Figs. 7 to 11 inclusive is of the 3-position type,that is, the handle 13 may be actuated from an off or intermediateposition toward the left to one closed position or toward the right toanother closed position, thereby providing the equivalent of asingle-pole double-throw switch. The upper stationary contacts 14 aremounted on an integrally formed cornbined bearing bracket and contactsupporting member 73. The member 73 has a generally U-shaped bearingbracket 74 having openings 75 therein for receiving a bearing pin 76.The member 73 also has integrally formed L-shaped arms 77 to which thecontacts 14 are attached. The member 73 is mounted on a middle terminalA and is electrically connected to the terminal A. One of the lowerstationary contacts is mounted on a terminal B and the other is mountedon a terminal C.

The bridging Contact member 2i has two integrally formed spring arms 24which function in the manner previously described. A left-hand togglespring 78 and a right-hand toggle spring 79 are provided. These togglesprings are independently operable and each one operates only the springarm 24' which it engages. The V-shaped end of each toggle spring has anopening 42 for receiving the projection on one of the spring arms 24'.The spring toggle 78 has spaced legs 81 having openings 82 therein forreceiving the bearing pin 76. Likewise, the spring toggle 79 has legs 83with openings 84 therein for receiving the bearing pin 76. The legs 83of the toggle 79 are spaced further apart than the legs 81 of the toggle78 to permit the legs 83 to straddle the legs 81 when assembled. Thetoggle 78 has an upwardly extending pin 85 which is disposed in a slot86 in an operating lever 8'7. Likewise the toggle 79 has a pin 88 whichis disposed in a slot 89 in the operating lever 87.

The switch may be assembled by inserting the projections 25 on thespring arms 24 into the openings 42 in the spring toggles 78 and 79. Thebearing pin 76 may then be inserted through the opening 75 in thehearing bracket 74, the openings 84 and 82 in the toggles 78 and 79through an opening 91 in a bearing bushing 92. The handle 13 may beinserted through an opening 93 in the operating lever 87 and threadedinto an opening 94 in the bearing bushing 92, and drawn tightly againstthe bearing pin 76 to'retain the bearing pin in position. The handle 13"and the toggle springs 78 and 79 are movable about the bearing pin 76.

Since the distance between the ends of the spring arms 24 is less thantwice the distance between the V-shaped ends of the toggle springs andtheir bearing axis, the toggle springs and the spring arms are understress when assembled in the switch. Thus, the assembly is un- 6 stableunless the operating handle 13" is in one of its three definitepositions.

When the operating handle 13" is in the off position, as shown in Fig.7, the contact members 22 carried by the bridging contact member 21engage the upper contacts 14, and the contact members 23 are disengagedfrom both of the lower stationary contacts 15. If the handle 13" ismoved in a counterclockwise direction, the right-hand end of thebridging contact member 21' will not move until the knife-edge bearingof the toggle spring 79 is substantially in alignment with the sides ofthe bridging contact member. At this point a condition of unstableequilibrium is attained and the right-hand end of the bridging contactmember 21' will snap downward to cause the contact 23 to engage thehight-hand lower stationary contact 14 as shown in Fig. 8.

Once the toggle spring 79 starts to move over-center, it will go all theway, as there is suflicient play in the lost-motion connection toprevent the operating handle from holding it. The length of each of theslots 86 and 89 in the operating lever 87 is considerably greater thanthe diameters of the pins and 88, thereby providing the lost-motionconnection between the operating lever and the toggle springs. It willbe noted that the position of the toggle springs 78 and the left-handend of the bridging contact member 21 is not changed by moving thehandle 13" to the left because of the lost-motion connection between thetoggle spring 78 and the operating lever 87.

When the switch is in the position shown in Fig. 8, an electricalcircuit is established between the terminals A and C through theright-hand lower stationary contact 15, the contact 23 on the right-handend of the bridging contact member 21', the upper contact 22 on theleft-hand end of the bridging contact member 21, the contact 14 on theleft-hand end of the member 73, and the bearing bracket 74 to theterminal A.

If the handle 13" is actuated to the right or in a clockwise directionfrom the position shown in Fig. 7, the bridging contact member isactuated to the position shown in Fig. 9. When in this position, anelectrical circuit is established between the terminals A and B throughthe left-hand stationary contact 15, the left-hand contact 23 on thebridging contact member 21', the righthand contact 22 on the bridgingcontact member 21, the right-hand stationary contact 14 on the member73, and the bearing bracket 74 to the terminal A. The lostmotionconnections beween the spring toggles 78 and 79 and the operating lever87 permit the desired snap action to be attained for either direction ofoperation of the handle 13".

As in the switch structure previously described, the spring togglemembers and the spring arms of the bridging contact member cooperate toprovide the force for maintaining contact pressure between the contactsof the switch. As in the previously described structure, the forceincreases as the operating handle is moved, thereby securing the snapaction which prevents the contact from burning. a

The operating handle 13" is stopped by the sides of the opening 12 inthe base 10' in either one of the on positions of the switch. The handle13" is retained in the OE position by the contacts 22 on the bridgingcontact member engaging both upper stationary contacts 14 and thestresses on both toggle springs being substantially equal, therebyobtaining a condition of stable equilibrium.

From the foregoing description, it is apparent that I have providedsnap-acting switches which are relatively simple in structure andprecise and positive in operation. The parts of the switch do notrequire extremely close manufacturing tolerances in order to obtain thedesired operation of the switch. Therefore, the switch may beeconomically manufactured and assembled.

Since numerous changes may be made in the above described constructionand different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all the mattercontained in the foregoing description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. An electric switch comprising, a stationary contact, a contact membermovable into and out of engagement with said stationary contact, aspring arm formed integrally with the contact member, said spring armbeing free to move at both ends, a pivotally mounted operating handle,spring toggle means engaging the spring arm, said spring toggle meansbeing pivotally mounted independently of said operating handle,lost-motion means operatively connecting the operating handle and thespring toggle means, said spring arm and said spring toggle meanscooperating to bias the contact member in a predetermined direction, andsaid spring toggle means being stressed when the operating handle isactuated to actuate the contact member.

2. An electric switch comprising, a stationary contact, a contact membermovable into and out of engagement with said stationary contact, aspring arm formed integrally with the contact member, a pivotallymounted operating handle, generally U-shaped spring toggle meansengaging the spring arm, pivotal means supporting said toggle meansindependently of the operating handle, lostmotion means operativelyconnecting the operating handle and the spring toggle means, said springarm and said spring toggle means cooperating to bias the contact memberin a predetermined direction, and said spring toggle means beingstressed when the operating handle is actuated to actuate the contactmember.

3. An electric switch comprising, spaced stationary contacts, a bridgingcontact member movable into and out of bridging engagement with saidstationary contacts, a spring arm formed integrally with the bridgingmember, said spring arm being free to move at both ends, a pivotallymounted operating handle, spring toggle means engaging the spring arm,said spring toggle means being pivotally mounted independently of saidoperating handle, lost-motion means operatively connecting the operatinghandle and the spring toggle means, said spring arm and said springtoggle means cooperating to bias the bridging contact member in apredetermined direction, said spring toggle means being stressed whenthe operating handle is actuated to actuate the bridging contact member,and said spring arm and said spring toggle cooperating through thelost-motion means to retain the operating handle in the position towhich it was last actuated.

4. An electric switch comprising, spaced stationary contacts, a bridgingcontact member movable into and out of bridging engagement with saidstationary contacts, a spring arm formed integrally with the bridgingmember, a pivotally mounted operating handle, generally U-shaped springtoggle means engaging the spring arm, pivotal means supporting saidtoggle means independently of the operating handle, lost-motion meansoperatively connecting the operating handle and the spring toggie means,said spring arm and said spring toggle means cooperating to bias thebridging contact member in a predetermined direction and said springtoggle means being stressed when the operating handle is actuated toactuate the bridging contact member, and said spring arm and said springtoggle cooperating through the lostmotion means to retain the operatinghandle in the position to which it was last actuated.

5. An electric switch comprising, a stationary contact, a contact membermovable into and out of engagement with said stationary contact, aspring arm formed integrally with the contact member, said spring armbeing free to move at both ends, a pivotally mounted operating handle,spring toggle means engaging the spring arm, said spring toggle meansbeing pivotally mounted independently of said operating handle,lost-motion means operatively connecting the operating handle and thespring toggle means, said contact member having an opening therein forreceiving the spring toggle means, said spring arm and said springtoggle means cooperating to bias the contact member in a predetermineddirection, and said spring toggle means being stressed when theoperating handle is actuated to actuate the contact member.

6. An electric switch comprising, a stationary contact, a contact membermovable into and out of engagement with said stationary contact, aspring arm formed integrally with the contact member, a pivotallymounted operating handle, generally U-shaped spring toggle meansengaging the spring arm, pivotal means supporting said toggle meansindependently of the operating handle, lostmotion means operativelyconnecting the operating handle and the spring toggle means, saidcontact member having an opening therein for receiving the spring togglemeans, said spring arm and said spring toggle means cooperating to biasthe contact member in a predetermined direction, and said spring togglemeans being stressed when the operating handle is actuated to actuatethe contact member.

7. An electric switch comprising, spaced stationary contacts, a bridgingcontact member movable into and out of bridging engagement with saidstationary contacts, a spring arm formed integrally with the bridgingmember, said spring arm being free to move at both ends, a pivotallymounted operating handle, spring toggle means engaging the spring arm,said spring toggle means being pivotally mounted independently of saidoperating handle, lost-motion means operatively connecting the operatinghandle and the spring toggle means, said bridging contact member havingan opening therein for receiving the spring toggle means, said springarm and said spring toggle means cooperating to bias the bridgingcontact member in a predetermined direction, said spring toggle meansbeing stressed when the operating handle is actuated to actuate thebridging contact member, and said spring arm and said spring togglecooperating through the lost-motion means to retain the operating handlein the position to which it was last actuated.

8. An electric switch comprising, spaced stationary contacts, a bridgingcontact member movable into and out of bridging engagement with saidstationary contacts, a spring arm formed integrally with the bridgingmember, a pivotally mounted operating handle, generally U-shaped springtoggle means engaging the spring arm, pivotal means supporting saidtoggle means independently of the operating handle, lost-motion meansoperatively connecting the operating handle and the spring toggle means,said bridging contact member having an opening therein for receiving thespring toggle means, said spring arm and said spring toggle meanscooperating to bias the bridging contact member in a predetermineddirection, said spring toggle means being stressed when the operatinghandle is actuated to actuate the bridging contact member, and saidspring arm and said spring toggle cooperating through the lost-motionmeans to retain the operating handle in the position to which it waslast actuated.

9. An electric switch comprising, spaced stationary contacts, a bridgingcontact member movable into and out of bridging engagement with saidstationary contacts, a spring arm formed integrally with the bridgingmember, said spring arm being free to move at both ends, a pivotallymounted operating handle, spring toggle means engaging the spring arm,said spring toggle means being pivotally mounted independently of saidoperating handle, lost-motion means operatively connecting the operatinghandle and the spring toggle means, said spring arm and said springtoggle means cooperating to bias the bridging contact member in apredetermined direction, said spring toggle means being stressed whenthe operating handle is actuated to actuate the bridging contact member,said spring arm and said spring toggle cooperating through 9 thelost-motion means to retain the operating handle in the position towhich it was last actuated, and said operating handle and said spring tiggle means being movable about the same axis.

10. An electric switch comprising, spaced stationary contacts, abridging contact member movable into and out of bridging engagement withsaid stationary contacts, a spring arm formed integrally with thebridging member, a pivotally mounted operating handle, generallyU-shaped spring toggle means engaging the spring arm, pivotal meanssupporting said toggle means independently of the operating handle,lost-motion means operatively connecting the operating handle and thespring toggle means, said spring arm and said spring toggle meanscooperating to bias the bridging contact member in a predetermineddirection, said spring toggle means being stressed when the operatinghandle is actuated to actuate the bridging contact member, said springarm and said spring toggle cooperating through the lost-motion means toretain the operating handle in the position to which it was lastactuated, and said operating handle and said spring toggle means beingmovable about the same axis.

11. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, at least one spring arm formed integrally with the bridgingmember, said spring arm being free to move at both ends, an operatinghandle pivotally mounted in the casing, spring toggle means engaging thespring arm, said spring toggle means being pivotally mountedindependently of said operating handle, lost-motion means operativelyconnecting the operating handle and the spring toggle means, said springarm and said springtoggle means cooperating to bias the bridging contactmember against certain of the stationary contacts, and said springtoggle means being stressed when the operating handle is actuated toactuate the bridging contact member.

12. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, at least one spring arm formed intergrally with the bridgingmember, an operating handle pivotally mounted in the casing, generallyU-shaped spring toggle means engaging the spring arm, pivotal meanssupporting said toggle means independently of the operating handle,lostmotion means operatively connecting the operating handle and thespring toggle means, said spring arm and said spring toggle meanscooperating to bias the bridging contact member against certain of thestationary contacts, and said spring toggle means being stressed whenthe operating handle is actuated to actuate the bridging contact member.

13. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, an operating handle pivotally mounted in the casing,pivotally mounted spring toggle means engaging the spring arms tosupport the bridging member, a pivotally mounted operating leveroperatively connecting the operating handle and the spring toggle meanswith a lost-motion connection, said spring arms and said spring togglemeans cooperating to bias the bridging contact member against certain ofthe stationary contacts, and said spring toggle means being stressed byactuating the operating handle to actuate the bridging contact member.

14. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, two pairs of oppositely disposed spring arms formed integrallywith the bridging member, an operating handle pivotally mounted in thecasing, pivotally mounted spring toggle means engaging the spring arms,a pivotally mounted operating lever operatively connecting the operatinghandle and the spring toggle means with a lost-motion connection, saidspring arms and said spring toggle means cooperating to bias thebridging contact member against certain of the stationary contacts, andsaid spring toggle means being stressed by actuating the operatinghandle to actuate the bridging contact member.

15. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, two pairs of oppositely disposed spring arms formed integrallywith the bridging member, an operating handle pivotally mounted in thecasing, pivotally mounted spring toggle means engaging the spring arms,a pivotally mounted operating lever operatively connecting the operatinghandle and the spring toggle means with a lost-motion connection, saidspring arms and said spring toggle means cooperating to bias thebridging contact member against certain of the stationary contacts, saidspring toggle means being stressed by actuating the operating handle toactuate the bridging contact member, and said operating handle and saidspring toggle means and said bridging contact member being movable aboutthe same axis.

16. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, a spring arm formed integrally with the bridging member, saidspring arm being free to move at both ends, spring toggle means engagingthe spring arm, bearing supporting means mounted in the casing, anoperating handle pivotally mounted in said supporting means, said springtoggle means being pivotally mounted in the casing independently of theoperating handle, lost-motion means operatively connecting the operatinghandle and the spring toggle means, said spring means cooperating tobias the bridging contact member against certain of the stationarycontacts, and said spring toggle means being stressed by actuating theoperating handle to actuate the bridging contact member.

17. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, a spring arm formed integrally with the bridging member,spring toggle means engaging the spring arm, bearing supporting meansmounted in the casing, said spring toggle means having integrally formedlegs pivotally mounted on said bearing supporting means, an operatinghandle pivotally mounted in said suporting means, lostmotion meansoperatively connecting the operating handle and the spring toggle means,said spring arm and said spring toggle means cooperating to bias thebridging contact member against certain of the stationary contacts, andsaid spring toggle means being stressed by actuating the operatinghandle to actuate the bridging contact member.

18. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, a spring arm formed integrally with the bridging member,spring toggle means engaging the spring arm, bearing supporting meansmounted in the casing, said spring toggle means having integrally formedlegs pivotally mounted on said bearing supporting means, an operatinghandle pivotally mounted in said supporting means, lostmotion meansoperatively connecting the operating handle and the spring toggle means,said spring arm and said spring toggle means cooperating to bias thebridging contact member against certain of the stationary conarm andsaid spring toggle.

tacts, said spring toggle means being stressed by actuating theoperating handle to actuate the bridging contact member, and saidoperating handle and said spring toggle means being movable about thesame axis.

19. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts,

oppositely disposed spring arms formed integrally with the bridgingmember, spring toggle means engaging the spring arms to support thebridging member, bearing supporting means mounted in the casing, saidspring toggle means having integrally formed legs pivotally mounted onsaid bearing supporting means, an operating handle pivotally mounted inthe casing, pivotally mounted lost-motion means connecting the handleand the spring toggle means, and said spring toggle means being stressedby actuating the operating handle to actuate the bridging contactmember.

20. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, spring toggle means engaging the spring arms, bearingsupporting means mounted in the casing, said spring toggle means havingintegrally formed legs pivotally mounted on said bearing supportingmeans, an operating lever pivotally mounted in the casing and engagingthe spring toggle means with a lost-motion connection, an operatinghandle secured to the operating lever, and said spring toggle meansbeing stressed by actuating the operating handle to actuate the bridgingcontact member.

21. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, spring toggle means engaging the spring arms to supportthe bridging member, bearing supporting means mounted in the casing,said spring toggle means having integrally formed legs pivotally mountedon said bearing supporting means, an operating lever pivotally mountedin the casing and engaging the spring toggle means with a lost-motionconnection, an operating handle secured to the operating lever, saidspring toggle means being stressed by actuating the operating handle toactuate the bridging contact member, and said operating lever and saidspring toggle means being movable about the same axis.

22. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, toggle springs engaging the spring arms to support thebridging member, bearing supporting means mounted in the casing, saidtoggle springs having integrally formed legs pivotally mounted on saidbearing supporting means, an operating handle pivotally mounted in thecasing, a pivotally mounted operating lever connecting the handle andthe toggle springs with a lost-motion connection, and said togglesprings being stressed by actuating the operating handle to actuate thebridging contact member.

23. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, separately operable toggle springs engaging the springarms, bearing supporting means mounted in the casing, said togglesprings having integrally formed legs pivotally mounted on said bearingsupporting means, an operating handle pivotally mounted in the casing, apivotally mounted operating lever connecting the handle and the togglesprings with a lost-motion connection, and said toggle springs beingstressed by actuating the operating handle to actuate the bridgingcontact member.

24. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, separately operable toggle springs engaging the springarms, bearing supporting means mounted in the casing, said togglesprings having integrally formed legs pivotally mounted on said bearingsupporting means, a three-position operating handle pivotally mounted inthe casing, a pivotally mounted operating lever connecting the handleand the toggle springs with a lost-motion connection, and said togglesprings being stressed by actuating the operating handle to actuate thebridging contact member.

25. In an electric switch in combination, a casing, stationary contactsdisposed in the casing in spaced relation, a bridging contact membermovable into and out of bridging engagement with said stationarycontacts, oppositely disposed spring arms formed integrally with thebridging member, separately operable toggle springs engaging the springarms, integrally formed contact and bearing supporting means mounted inthe casing, said toggle springs having integrally formed legs pivotallymounted on said bearing supporting means, a threeposition operatinghandle pivotally mounted in the casing, a pivotally mounted operatinglever connecting the handle and the toggle springs with a lost-motionconnection, and said toggle springs being stressed by actuating theoperating handle to actuate the bridging contact member.

References Cited in the file of this patent UNITED STATES PATENTS1,650,348 Hanny Nov. 22, 1927 1,797,466 DeHufi Mar. 24, 1931 2,129,151Raney Sept. 6, 1938 2,135,864 Weber Nov. 8, 1938 2,574,429 Wood Nov. 6,1951 2,608,628 Dietrich Aug. 26, 1952 FOREIGN PATENTS 929,963 FranceJuly 28, 1947 614,812 Great Britain Dec. 23, 1948 985,619 France Mar.14, 1951 Feb. 14, 1956 c, Y S 2,734,960

SAFETY SIGNAL DEVICE FOR HYDRAULIC BRAKE SYSTEMS Filed Oct. 5, 1953 V{IIIIIIIIIIIIIQVIIIIIIIIIIIIIIIII INVENTOR Charles G. Reynolds WM 6 [MMATTVJ

